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Finding the Fourth Proportional to 520.57, 780.85 and 155.39

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Solution

The fourth proportional to 520.57, 780.85 and 155.39 is: 233.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.57 : 780.85 = 155.39 : x
  2. Step 2: Convert to fraction form
    520.57/780.85 = 155.39/x
  3. Step 3: Cross multiply
    520.57x = 780.85 × 155.39
  4. Step 4: Simplify right side
    520.57x = 121,336.28
  5. Step 5: Solve for x
    x = 121,336.28/520.57
  6. Step 6: Final answer
    x = 233.08

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.